Wood-bending machine



Nov. 20, 1956 K. MICHAELIS woon-BENDING MACHINE ets- Sheet l 2 She F`iled Nov. 8, 1952 Novi; 20, 1956 K. MICHAELIS 2,771,109

WOOD-BENDI NG MACHINE Filed Nov. 8, 1952 2 Sheets-Sheet 2 6 43 Fig. 4 42United States Patent 0 WOOD-BENDING MACHINE Karl Michaelis, Paris,France Application November 8, 1952, Serial No. 319,587

7 Claims. (Cl. 144-254) This application is a continuation-in-part of mycopending application Serial No. 166,085, led June 5, 1950 (nowabandoned).

The invention to be protected in the present application relates towood-bending machines of the type disclosed in my U. S. Patent No.2,089,078, in which an abutment member in the form of a roll extendingacross the board or panel to be bent which had previously been renderedpliable, forces the wood to Wrap itself around the curved surface of aformer drum to which it had been secured.

In this machine, in order to make bends of different radii, the drummust be supported in exactly horizontal position in order to prevent thewood from being bent along lhelicoidal lines. However, the lifting ofheavy equipment without changing their horizontal position requirescareful and expensive machining of the glide blocks.

It is an object of the present invention to provide means forsupporting, lifting and lowering the drums in a simple and inexpensivemanner and for lixing them firmly at different levels.

According to this invention the drums are supported near one end of alever pivoted on a horizontal axle which is supported by the machinebed. I prefer using a double-aimed lever, whose other lever arm carriesthe motor serving to turn the drum. The motor acting as a counter-weightrenders the adjusting of the drums easy.

The balanced lever preferably has the form of a rigid girder, forinstance of the box type. In order to avoid torsional stresses acting onthe lever, it may be useful to provide a pair of such levers for thesupport of the drum and the motor.

I further provide means for firmly connecting the free end of the drumaxle, after it has been brought into position, with the machine bed.

Means should also be provided for changing the position of the abutmentmember relative to the point at which the work is fixed to the drum.Obviously, in bending a thick board or panel, the abutment member shouldbe applied to the work at a greater distance from the curved drumsurface, than in the case of a thinner panel.

In the drawings aflixed to this specification and forming part thereof,an embodiment of the invention is illustrated diagrammatically by way ofexample.

In the drawings Fig. 1 is a vertical longitudinal section of a bendingmachine, in which a horizontal work table supports a hot plate servingfor rendering the Wood pliable by dry heat.

Figs. 2 and 3 are a longitudinal section and partly an end View,respectively, drawn to a larger scale, of a device for fixing the workto the drum.

Figs. 4 and 5 are an axial section and an end view, respectively, of adrum.

, Figs. 6 and 7 are a front View and an end-view, re-

2,771,109 Patented Nov. 2,0, 1956 spectively, of the abutment memberhaving the form of a roll and of means for Varying its position relativeto the drum.

Referring to the drawings and rst to Fig. 1, 1 is the rear wall of apair of parallelly spaced walls forming the machine bed. These walls areconnected with each other by the work table 2 and by bracing members 3and 4. A channel iron is mounted on the inner side of each wall 1. Fromeach wall 1 extends a rigid arm 6.

move a short distance outwardly and will pushwthe top Between the twoarms is supported an axle 11, on which is pivoted a double-armed leverin the form of a girder 7 (or a pair of such girders) for rockingmotion. On the rear arm of this girder an electro-motor 18 is mounted ona plate 19 supported by a horizontal arm 17 of a lever 9, the lower endof which embraces a pin 8 on a nut 14, which surrounds a screw spindle15 supported in bearings 25. By rotating this spindle by means of thehand wheel 31, the lever can be moved and the girder 7 rocked -about theaxle 11 to lift or lower its free end, in which is supported the drumaxle 16.

The girder and the weight of the drum 21 being counter-balanced eitherentirely or partly, by the weight of the motor 18, adjustment of thedrum in the vertical direction is easy and the drum is locked inposition by the arm 9 and nut 14.

A gear 20 driven by the motor and its speed reducer (not shown) drivesthe sprocket 13 and by means of a chain 12 the sprocket 23 keyed on asleeve 26 (Fig. 4) which rides on the axle 16 and, by means of pins 49,grips one end wall 46 of the drum which can then be rotated directly bythe motor 18.

The free end of the girder 7 can be xed in its position relative to thework also by means of a threaded connecting rod 41 (Fig. l) pivoted onan axle 42 supported in a bearing 43 on the front arm 6. The free end ofthe rod 41 can .be introduced in a slot 71 in the free end of the axle1'6 and a large nut 44 riding on the threaded rod will serve as a restfor the axle, which is supported 'at the end of the girder 7. The drum21 shown in Figs. 4 and 5 is closed by two heads 46 and 47 formed withperforations 48. The sleeve 26 encircling one end of the axle andcarrying the driven sprocket 23 carries pins 49, which, when the drumIis slipped on the axle enters the perforations 48 of theA drum head,46.`

Another sleeve 50 surrounding the free end of the axle 16 also carriespins 51 which enter the perforations 52 in the drum head 47. Both thesleeves 26 loosely on the axle 16.

VThe drum shell is heated by hot air. Resistance wires 53 extendingbetween discs 54 mounted on the axle and fed with current by means ofleads 55 entering the supported end of the axle and projecting radiallythrough the perforation 56 of the axle wall provide the heat for heatingup the air enclosed in the drum shell.

The clamping of the workpiece 40 (Figs. 2 and 3) to the drum 11 can beetfectedby hand with the aid of a device such as shown in Figs.` 2 and3. The heavy steel bar 57 of square cross-section is suspended forsliding motion by means of pins 58 in a rigid channel 59, to the end ofwhich are hinged by their middle arms 60 hooks 61 of inverted F-section.The horizontal arms 62 of the hooks canry vertical' screw bolts 63. Thefree ends of the hooks are gripped `by the upturned ends 64 of a leafspring 65, which is acted upon by a screw bolt 66 passing through aperforation in the middle section of the spring. The springis forceddownwardly by a Harige 67 formed on the bolt 66, when this bolt isscrewed down by means of the hand wheel 68. When the spring isflattenedv by the pressure exerted by the screw bolt 66, vits ends insliding on the channel 59 will and 50 ride ends of the hooks 61outwardly, whereupon the bottom ends are swung inwardly towards the drumheads, causing the bolts 63 to grip from. below the ends of the drumshell 68. Onthe bolt 66. being screwed further down, it` comes to-` reston the bar 57 and raises the channely 59 until the bolts 63 have firmlygripped the cylinder shell and thereby clamped the workpiece between thebar and the shell of the drum. On. the bolt 66 being loosened again theleaf spring will return to its original form and will become shorter,pulling the top ends of the hooks inside and the bottom ends of thehooks towards the outside, thus disengaging the device from the drum.

The bending roll 70 (Figs. l, 6 and 7) which acts as an abutment met bythe vworkpiece when this latter is pulled. oi the worktableA and triesto rise isv mounted in ball bearings (not shown) in the endk walls 71 ofa carrivage 72 of channel section, open at the bottom. The end walls 71carry on the outside lugs '73 extending at an angle to the carriage topand bottom edges. The

lugs are arranged to slide in the inclined guide grooves o 74 (Fig. l)formed on the inner sides of the horizontal channels 5. A vertical lug7S formed with a screw threaded perforation 'I6 is-mounted on thecarriage top. It rides on a threaded spindle 77 supported in inclinedpositions in bearings 78. By rotating the spindle with the aid of acrank handle 79 placed on its projecting end, the roll 70 can be shiftedboth relative to the drum 21 and to the work on the heater plate 37which is supported by the worktable 2. By shifting the bending roll inthis manner, not only the distance of the roll from the drum, but alsothe distance of the roll from the surface of the heater plate and workis increased or decreased, in accordance with the thickness of the Work.

The heater plate 37 is heated by an electric current.

In order to exchange a drum for another one of smaller or largerdiameter, the rod 41 is Withdrawn from the slot 71 of the shaft 16 andpulled back by the counterweight, the right hand sleeve 50 is taken olf,the drum is slid along the shaft and removed, the new drum slid on,until thepins 49 of the left hand sleeve have entered the perforationsof the head 46 and the right hand sleeve put in place again withthe pins51 entering the perforations of the head 47.

The girder 7 is then adjusted by turning the screw spindle by means ofthe wheel 31, until the drum contacts the work.

I wish it to be understood that I do not desire to be limited to thedetails disclosedin the foregoing specification and in the drawings forobvious modifications will occur to a person skilled in the art.

I claim:

1. In a wood-bendingmachine the combination, with a machine bed, of adrum shaft, a former-drum on said shaft and an abutment memberpositioned in opposed relation to the drum for cooperation with the drumto contact opposite sides of the work extending between them, a leverpivoted to said machine bed on a horizontal axis for rocking movement ina vertical plane and supporting, lifting and lowering said shaft,mounted at one end, in exactly horizontal position, means at the rearend of said lever for fixing said lever and shaft at any leveldetermined by the drum radius and means for rotating said drum.

2. In a wood-bendingmachinethe combination, with a machine bed, of adrum shaft, a former-drum on said shaft and an abutment member`positioned in opposed relation to the drum for cooperation with the drumto contact opposite sides of the work extending between them, adouble-armed lever pivoted to said machine bed on a horizontal axis forrocking movement in a Verticalplane and supporting, lifting andloweringsaid shaft,

mounted at one end, ,in exactly horizontal position, means atgthe rearendof said lever for ixingsaid'leverand shaftaty any-Y level determined.by, thev drum radius and means` for rotating said drum.

3. In a wood-bending machine the combination, with a'machine bed, of adrum shaft, a former-drum on said shaft and lan abutment memberpositioned in opposed relation to the drum for cooperation with the drumto Contact opposite sides of the work extending between them, adouble-armed lever pivoted to said machine bed on a horizontal axis forrocking movement in a vertical plane and supporting, lifting andlowering said shaft, mounted at one end, in exactly horizontal position,means at the rear end of said lever for fixing said lever and shaft atany level determined by the drum radius and means; for rotating saiddrum mounted on. the other end of said lever.

4. In a wood-bending machine the combination, with a machine bed, of adrum shaft, a former-drum on said shaft and an abutment memberpositioned in opposed relation to the drum for cooperation with the drumto contact opposite sides of; the work extending between them, means on,said machine bed for simultaneously adjusting said abutment member inhorizontal and in vertical position, a lever. pivoted to said machinebed on a horizontal axisY for rocking movement in a vertical plane andsupporting, lifting and lowering said shaft, mounted at one end, inexactly horizontal position, means at the rear endv of said lever forfixing said lever and shaft at any level determined by the drum radius`and means for. rotating saidY drum.

5. In a wood-bending machine the combination, with ay machine bed, ofadrum shaft, a former-drum on said shaft and an abutment memberpositioned in opposed relation to the drum for cooperation with the drumto contact opposite sides of the work extending between them, means onsaid machine bed for displacing said abutment: memberv in aplaneinclined at an acute angle relative to the plane of the drum shaft,a lever pivoted to said machine bed on. a horizontal axis for rockingmovement in a vertical plane and supporting, liftingV and loweringsaid`shaftmounted at one end, in exactly horizontal position, means atthe rear end of said lever for fixing said lever and shaft at any leveldetermined` by the drum radiusand meansfor rotating said drum'.

6. In a wood-bending machine the combination, with a machine.y bed, of adrum shaft, a former-drum on said shaft and an abutment memberpositioned inv opposed relation to the drum for cooperation. with thedrum to contact opposite. sides of the work extending between them,alever pivoted to said'machine bed'on a horizontal axis for rockingmovement in a vertical plane and supporting,.lifting'` and lowering saidshaft, mounted at one end, in exactly horizontal position,` means attherear end of said lever` for xing said. lever and shaft at any leveldetermined by the drum radiusland means for rotating said drum.

7. In a wood-bending` machine the-combination, with la machine bed, of-a drum ax1e. two-sleeves rotatable' on said axlera former-dromen saidsleeves and an abutment member positioned in opposed relation to thedrum for, cooperationwith the drum to contact opposite sides of the'work extending between them, a-lever pivoted to said machine bed on ahorizontal axis for rocking movement in a-vertical plane and supporting,lifting and lowering said axle, mounted at one end, in exactlyhorizontal position, means at the rear end of said lever` for fixingsaid lever and axle at any level determined bythe drum radius and meansfor rotating said drum.

References Cited in' the file of this patent UNITI-EDl STATES PATENTS360,344 Godfrey let al Mar. 29, 1887 1,547,096 Crouse. Iulyf 21, 1925`1,733,532 Elliot' Oct. 29; 1929 1,743,714 Jahn Jan.A I4', 19'30A2,373,567.' Jackson Apr. 10,1 1945 2,520,457 Cook Aug. 29, 1950

